上海市市区、郊区NO2、SO2和PM10的时空变化规律及相关性分析

在对上海市嘉定区大气污染物SO2、NOx和PM10连续1年的观测基础上，结合上海环境状况公报的数据，探讨了市区、郊区大气污染物的空间和时间变化规律。结果表明，2005年中NO2、SO2和PM10的质量浓度在市区和郊区均是冬春两季高，夏秋两季低；NO2、SO2和PM10浓度在市区要高于郊区；郊区大气污染物的月变化幅度要比市区大，市区PM10污染有增加趋势。根据气象条件分析，嘉定区周边工业污染对NO2、SO2和PM10的浓度有贡献，市区NO2、SO2和PM10的质量浓度则与机动车尾气、工业燃煤，建筑扬尘和道路扬尘等诸多因素有关。相关性分析表明，上海市NO2、SO2和PM10相互之间存在比较强的相关性。     

重庆市区2000年前大气环境质量的灰色预测

本文运用灰色系统理论,预测了重庆市区1990年至2000年的大气质量变化趋势。     

城市大气环境质量的协同评价

根据系统科学思想,在城市大气环境质量（ＡＡＱ）评价中,对＂本质＂与＂异质＂ＡＡＱ等量齐观,并强调污染物的低浓度长时间效应．本文探讨了两者的协同评价方法,利用常规监测资料对５个城市作了实例分析．研究结果与实际情况有较好的一致性．     

Extreme value analysis of Munich air pollution data

We present three different approaches to modelling extreme values of daily air pollution data. We fitted a generalized extreme value distribution to the monthly maxima of daily concentration measures. For the exceedances of a high threshold depending on the data, the parameters of the generalized Pareto distribution were estimated. Accounting for autocorrelation, clusters of exceedances were used. To obtain information about the relationship of the exceedance of the air quality standard and possible predictors we applied logistic regression. Results and their interpretation are given for daily average concentrations of ozone and nitrogen dioxide at two monitoring sites within the city of Munich.     

厌氧-吹脱-好氧-吸附法处理酱油废水

针对酱油废水的高CODCr、高色度、高挥发酸以及含盐的特点，设计了用厌氧-吹脱-好氧-吸附法处理酱油废水的工艺。实验结果表明，该工艺对酱油废水的处理有较好的处理效果。当厌氧进水的CODCr分别为6000～8000和1500～2000mg／L，色度分别为5000和1800倍左右时，厌氧反应的水力停留时间(HRT)分别为3～4和2d，吹脱池的停留时间为16h，气水比为0．01m^3／L，好氧反应器和煤渣吸附池的停留时间分别为14～18和14～16h时，该流程对废水CODCr的总平均去除率分别达到90％和82．7％左右，对色度的总平均去除率分别为76．7％和86．5％。     

Distribution,sources and pollution status of Pb in indoor and outdoor dusts of Kerman City,SE Iran

The aims of this study were to explore the status of pollution and the temporal/spatial distribution of indoor and outdoor dust-Pb in the city of Kerman (SE Iran), located in a dry playa and arid climatic zone. Flat panes were laid at appropriate locations, in the indoor and the outdoor spaces of selected one-story houses in different areas of the city, to collect dust samples. Forty-two samples were taken and analyzed using the ICP-MS method. The measurements have shown that the outdoor dust-Pb concentrations varied from 23.7 to 275.2?mg kg^?1, with a mean value of 71.8?mg kg^?1, and indoor dust-Pb concentrations ranged from 47.6 to 150.2?mg kg^?1, with a mean value of 89.6?mg kg^?1. Based on these measurements, Pb was enriched in the outdoor and the indoor dust samples up to 48.8 and 29.4 times, respectively. Dilution, as a result of prevalence of geogenic dust in the outdoor space, is expected to be the main cause of the temporal differences. This study has shown that the eastern part of the city is more polluted compared to the other parts, and, because of the stable air conditions, the concentration of Pb in the summer dust is higher than the other seasons.     

Dioxin removal in “energy from waste plants” - comparison of air pollution control methods

The graph below shows the emitted dioxin - equivalents (Eadon) in grams per year in flue gas from municipal solid waste incinerators with various air pollution control methods for plants of capacity of 200 000 ton municipal solid waste (MSW) per year.

Full-size image (15K)

With optimized combustion and an effective air pollution control system the emissions of dioxins can be kept very low (concentrations below 0.1 ng/m³n).

With a very effective air pollution control system the total emission from all Swedish MSW-incinerators burning approximately 1.5 Mton/year will by 1990 be below 2 g/year - a drastic reduction from approximately 15 g today. As the total dioxin - equivalent emission to the environment in Sweden in the year 1987 was almost 500 g we see that municipal waste incineration really is on the way to solve their dioxin problem.     

Sensitivity analyses of woody species exposed to air pollution based on ecophysiological measurements

GOAL, SCOPE AND BACKGROUND: Air pollution has been of a major problem in the Pearl River Delta of south China, particularly during the last two decades. Emissions of air pollutants from industries have already led to damages in natural communities and environments in a wide range of the Delta area. Leaf parameters such as chlorophyll fluorescence, leaf area (LA), dry weight (DW) and leaf mass per area (LMA) had once been used as specific indexes of environmental stress. This study aims to determine in situ if the daily variation of chlorophyll fluorescence and other ecophysiological parameters in five seedlings of three woody species, Ilex rotunda, Ficus microcarpa and Machilus chinensis, could be used alone or in combination with other measurements for sensitivity indexes to make diagnoses under air pollution stress and, hence, to choose the correct tree species for urban afforestation in the Delta area. METHODS: Five seedlings of each species were transplanted in pot containers after their acclimation under shadowing conditions. Chlorophyll fluorescence measurements were made in situ by a portable fluorometer (OS-30, Opti-sciences, U.S.A). Ten random samples of leaves were picked from each species for LA measurements by area-meter (CI-203, CID, Inc., U.S.A). DW was determined after the leaf samples were dried to a constant weight at 65 degrees C. LMA was calculated as the ratio of DW/LA. Leaf N content was analyzed according to the Kjeldhal method, and the extraction of pigments was carried out according Lin et al. RESULTS AND DISCUSSION: The daily mean Fv/Fm (Fv is the variable fluorescence and Fm is the maximum fluorescence) analysis showed that Ilex rotunda and Ficus microcarpa were more highly resistant to pollution stress, followed by Machilus chinensis, implying that the efficiency of photosystem II in I. rotunda was less affected by air pollutants than the other two species. Little difference in daily change of Fv/Fm in I. rotunda between the polluted and the clean site was also observed. However, a relatively large variation of Fv/Fm appeared in the other two species, particularly in M. chinensis, suggesting that they were more sensitive to air pollutants than I. rotunda. The mean LA was reduced for all species growing at the polluted site. The mean LMA for all species exceeded the sclerophylly threshold given by Cowling and Campbell and increased for those under pollution stress, which could be explained as one of the acclimation strategies for plants to air pollution stress. Little difference in leaf chlorophyll content was observed in F. microcarpa and M. chinensis, while remarkable differences were found in I. rotunda growing at the polluted and the clean site. Content of leaf carotenoids was largely reduced in I. rotunda growing at the polluted site, but increased in F. microcarpa and M. chinensis, compared with plants growing at the clean site. Plants growing at the clean site had a lower leaf N content than those growing at the polluted site. In addition, species with a higher resistance to pollution stress showed less difference in leaf N content than those sensitive species. CONCLUSION: Based on Fv/Fm measurements of the three woody species, I. rotunda showed the highest resistance to air pollutants from ceramic industries, followed by F. microcarpa. M. chinensis was the most sensitive species to air pollution, had lowest capacities to cope with the air pollution stress, which was consistent with visual injury symptoms observed in the crown profiles of plants at the polluted site. Fv/Fm, LAM, LA, leaf pigments and N content could be used alone or in combination to diagnose the extent of the physiological injury. The ratio of Fv/Fm, however, was the best and most effective parameter. RECOMMENDATION AND OUTLOOK: Tree species which have higher air-pollutant resistance, as diagnosed by such ecophysiological parameters, should be considered first and planted widely for urban afforestation or forest regeneration in areas where the forest was seriously degraded or forest health was markedly effected by the same kind of air pollutants.     

The impacts of different kinds of dust events on PM10 pollution in northern China

In this study the frequencies of PM₁₀ (as key urban pollutant) in 14 key environmental protection cities in northern China were analyzed. It follows that the PM₁₀ concentration in the high-frequency period is higher with an extent 0.009–0.066 mg m⁻³ than in the low-frequency period of 2001–2002. Further the impacts of three kinds of dust events on the PM₁₀ concentration in four cities (Beijing, Hohhot, Xi’an and Lanzhou) were explored. The results showed that different kinds of dust events have different influences on variation of PM₁₀ concentration in these four cities. In Lanzhou and Hohhot, which are near the source areas of dust events, the contribution degree of these three dust events to the PM₁₀ is: floating dust>dust storm>blowing dust. Whereas, in Beijing and Xi’an situated in dust event passing areas, the mean value of PM₁₀ concentration is higher in blowing dust than in floating dust (no dust storm). In addition, the influences of dust events on PM₁₀ concentration are different in the cities on different dust event paths. In Beijing and Hohhot (on the northern path), the high PM₁₀ concentration is usually caused by blowing dust. But in both Lanzhou and Xi’an (on the western/northwestern path) the high PM₁₀ pollution concentration is usually caused by floating dust.     

Assessment of contribution of SO2 and NO2 from different sources in Jamshedpur region, India

Contribution of pollution from different types of sources in Jamshedpur, the steel city of India, has been estimated in winter 1993 using two approaches in order to delineate and prioritize air quality management strategies for the development of region in an environmental friendly manner. The first approach mainly aims at preparation of a comprehensive emission inventory and estimation of spatial distribution of pollution loads in terms of SO₂ and NO₂ from different types of industrial, domestic and vehicular sources in the region. The results indicate that industrial sources account for 77% and 68% of the total emissions of SO₂ and NO₂, respectively, in the region, whereas vehicular emissions contributed to about 28% of the total NO₂ emissions. In the second approach, contribution of these sources to ambient air quality levels to which the people are exposed to, was assessed through air pollution dispersion modelling. Ambient concentration levels of SO₂ and NO₂ have been predicted in winter season using the ISCST3 model. The analysis indicates that emissions from industrial sources are responsible for more than 50% of the total SO₂ and NO₂ concentration levels. Vehicular activities contributed to about 40% of NO₂ pollution and domestic fuel combustion contributed to about 38% of SO₂ pollution. Predicted 24-h concentrations were compared with measured concentrations at 11 ambient air monitoring stations and good agreement was noted between the two values. In-depth zone-wise analysis of the above indicates that for effective air quality management, industrial source emissions should be given highest priority, followed by vehicular and domestic sources in Jamshedpur region.